The present invention relates to an apparatus for clamping a flattened tube in a diffusion device. More particularly, the present invention relates to an apparatus for sealing a semi-permeable membrane in a dialysis device.
A number of apparatuses for closing tubular membranes are known. For example, U.S. Pat. No. Re 27,510 discloses a device in which the ends of a tubular membrane are folded around a highly elastic terminal tube 9 and pulled together under strong friction so as to be leak-proof. The patentee thus employs a conical bore 8 of a confining rim 10 in the outer casing 13 as best shown in FIG. 4 of the patent.
U.S. Pat. No. 3,712,474 teaches another such device which includes connector units 52 and 54 as best shown by FIG. 6 of the patent. In each unit, patentee includes a substantially resilient body portion 60 in a relatively less flexible cup element 62. By closely conforming the internal cup dimension to that of the body and by forming the body of a substantially resilient material, a snug fit is provided. Moreover, at least one O-ring 72 supported by the body insures a better fluid tight seal and prevents a possibility that the membrane will pull loose. Similar teachings are contained in U.S. Pat. Nos. 3,709,367 and 3,743,098.
U.S. Pat. No. 3,880,760 discloses yet another such device which includes a core cover section 2 adapted to mate with a core base section 1 with the ends of the tubular membrane therebetween. A similar structure is employed at the other end of the tubular membrane as shown by FIG. 2 of the patent. The core cover and core base sections are provided with seals 5 and 6 to seal the membrane tube 9 with the open end 7 of the blood inlet conduit within the membrane tube.
In a similar vein is U.S. Pat. No. 3,962,095 which discloses blood inlet and outlet means 26 for connection with arterial and veinous lines attached to a casing 22. The cover plates 28 are secured to the casing by means of screws 30. The cover plate 28 and the casing 22 carry seals 32 to seal the free ends of the membrane tube 12 with the blood inlet and blood outlet means 26.
U.S. Pat. No. 4,059,530 discloses blood inlet and outlet ports in a dialyzer membrane tube 3 comprising a connector 30 connected to a header 32 through a hole in the membrane. The header 32 is thus located internally in the tubular membrane. A locking disc 33 locks the membrane tube 3 against one wall of the header 32. The header is provided with internal chambers 35 communicating with the interior of the tubular membrane 3. The end of the tube is shown squeezed between connector 30 and a wall opposite the connector.
Other similar devices are shown in U.S. Pat. No. 3,963,621, British Pat. No. 1,417,446 and British Pat. No. 1,433,512. U.S. Pat. No. 3,963,621 merely states that a tube 18 communicates conventionally with the end 20 of a membrane 16. FIG. 3 of British Pat. No. 1,433,512 shows a membrane tube 2 pleated around a rigid connecting plug 38. Medical plaster 41 is applied around the membrane tube and the tube is secured by means of two knotted cords 42 and 43 in the annular grooves 39 and 40. British Pat. No. 1,417,446 merely discloses that the core 1 includes an opening in which a sleeve 31 fits so that the blood tube 12 can be connected to the membrane tube 2.